1. Field of the Invention
The present invention relates to an air conditioner.
2. Description of the Related Art
A compressor drive device incorporated in a conventional air conditioner is configured to block power distribution to a motor by opening a contact point (a thermostat) serially connected to a motor winding at the time of increase of pressure or temperature inside a compressor, thereby preventing abnormal increase of pressure or temperature in the compressor. In the compressor drive device, when the winding temperature of the motor has reached a predetermined temperature to be protected, a phase current of a phase in which the contact point is provided is blocked by opening the contact point, and a current sensor detects that a phase current value of the phase in which the contact point is provided is zero, and all the three-phase current outputs are stopped based on an output of the current sensor (see, for example, Japanese Patent Application Laid-open No. 2007-318824).
However, in the conventional technique represented by the above patent document, power distribution to the motor is blocked at the time of increase of pressure or temperature inside the compressor, which prevents abnormal increase of the pressure or temperature in the compressor. However, it cannot be specified whether the cause of shutdown of the compressor is due to abnormal pressure or other than the abnormal pressure (for example, overcurrent, abnormal bus voltage, or open-phase abnormality).